I have a built up b16a dohc vtec from japan in a 95 hatch. Forged pistons rods, cams, injectors, big fuel pump, headers, intake. The hatch has an rpm gauge with the red line at 7000 rpms. The original motor was a sohc non vtec. I was told at the local meet that the motor I have actually does not red line until 8200 rpm. Does any one know how high I can safely rev my motor

 

First gen B16A redlines at 8200. Second gen B16A redlines at 8500 MT, 8200 AT.

Have your car professionally tuned, and let your tuner decide how high your motor can rev.

 

It could use a tune for me to get optimal hp but i plan bolting on a turbo and running a p16 ecu in a months time. I will get it tuned then.

 

p16?

 

Get it tuned now.

 

Is there a rev limiter on your car? Make sure it's kicking in at 8500/8200

 

i had a b16a second gen and it had vtec x over at 5500 and cut off was at like 87 or 8800 on a stock p30 ecu

 

I found out that it was tuned by the previous owner. It does have a rev limiter. I can shift at 8500 1st-4th but 5th at 190 km/h the rev limiter kicks in at 7 grand.

 

What ecu is currently in the car

 

jdm ecus are speed limited

 

I am not sure what ecu it is. Maybe a p28. It's the ecu that came with the Jdm motor.

 

then it should be a p30...

if it was tuned it would not cut off at 7 in 5th...

thats a speed limiter and is only present on JDM OEM UNTOUCHED NON CHIPPED/PROGRAMMED ecus.

 

btw speed limiter is 118 mph IIRC

 

118 mph is 190 kmh. I will ask my mechanic if he tuned it. You would think if he put in a big pump and injectors, skunk 2 cams he would do a tune.

So my buddy said that I should be able to redline allittle higher than 8500 because I have forged pistons, rods and darton sleeves. Is that true?

 

No.

 

I think the valvetrain is a more important aspect of how high you can safely rev.

 

Valvetrain, rotating assembly, oil system. You need all three to safely rev high. So far all I've heard from OP is 1.5/3. 50% isn't 100%.

 

It has an upgraded valve train. We put a new head on it when we rebuilt the bottom end. So I talked to my mechanic. It's the stock ecu. He said that he "flashed" it when he did the cams and injectors.

 

If you rev it out all the time be sure your valve lash/timing belt is in spec or you will suffer bent/burnt valves accordingly. What S2 cams are you running anyway?

 

The cams are turbo friendly because that is my ultimate goal. I don't know what model they are.

 

"Cams" != upgraded valvetrain. It seems you don't know much, if anything, about this motor.

 

no he didnt

so you dont know what's in your motor?

 

very very VERY simple solution, have the car tuned by a pro and set the limit just after peak power, people always want high revs but they don't realize all they are doing is going slower and hurting their motor.

if you are doing more mods and then getting it tuned keep the car under, say 5k until then just to be safe.

once you do ANY mod to the engine valvetrain or any internals the stock tune, and with that, rev limit goes out the window.

if you make 150hp at 5000 and 140hp at 6000 why rev past 5? your only losing power even if the motor can handle it

 

pull the ECU from the car and remove the Phillips screws holding the cover on, is there a removable chip in there? no? no one has tuned or "flashed" your ecu.

 

It's more complex than just "where do you stop making power". In a perfect world, you would redline just before peak mean power through the shifted power band hits a negative delta, and fuel/ignition cut just after that. I'm not going to go into the math explaining why that's true - feel free to learn calculus, or trust me on it.